In 1939, aluminium bronze replaced copper and, in 1940, stainless steel replaced nickel.

When fiber replaces copper for long distance calls and Internet traffic, it dramatically lowers costs.

Another $9 billion is being spent overseas each year on replacing copper with fiber.

During the Iron Age, iron became the dominant form of metal used in the British Isles, replacing copper and bronze.

It is thought that through trade with India and later Portugal Zimbabwe started to value gold as prestige metal, however it did not replace copper.

In 1906, bronze replaced copper for the lowest three denominations; in 1907, a cupro-nickel one-anna coin was introduced.

However, no one alloy has emerged to replace copper as the industry standard, and alloy development is a very active area.

Eventually, optical wiring will replace copper, allowing for faster speeds.

PEX tubing is widely used to replace copper in plumbing applications.

However, the economic case for replacing existing copper just isn't there.